1. Field of the Invention
This invention relates, generally, to bite blocks. More particularly, it relates to a bite block having enhanced utility because it accommodates the fingers of the physician and certain medical instruments.
2. Description of the Prior Art
Bite blocks are used to hold open the mouth of a patient when an endoscope or other surgical instrument is inserted down the patient's throat and into his or her stomach or intestines, for example. Typically, bite blocks include a hollow mouthpiece upon which the patient bites when the mouthpiece part of the bite block is inserted into the patient's mouth. A flange surrounds the mouthpiece and, theoretically at least, insures that only the mouthpiece itself will enter the patient's mouth, i.e., the flange overlies the patient's lips and is intended to be too large to enter the patient's mouth; thus, it serves as a retainer for the hollow mouthpiece. The hollow mouthpiece defines a tunnel or bore through which the surgical instrument is inserted. For example, a surgical instrument such as an endoscope, as aforesaid, may be inserted through the bore defined by the mouthpiece. Without the bite block, a sleeping patient might involuntarily or reflexively bite down on the endoscope or other device and injure his or her teeth; a fully awake patient might also do the same.
Insertion of the surgical instrument is somewhat problematical; most physicians like to guide the instrument down the patient's throat with their fingers, but often the bite block itself interferes with such finger utilization. In all of the known bite block designs, the opening in the hollow mouthpiece is too small to accommodate one or more surgical instruments and one or more fingers at the same time. If the physician pulls the patient's lips back in an effort to get around the flange that surrounds the mouthpiece, a risk is created that the bite block could fully enter into the patient's mouth since such pulling back on the lips defeats the purpose of the flange. Since bite blocks are usually made with a hard plastic material, such unintentional insertion could result in trauma to the patient's mouth.
Numerous bite block designs have been patented over the years, but an effective bite block that allows the physician to guide the instrument into position with ease has heretofore eluded inventors. For example, U.S. design U.S. Pat. No. 283,158 to Jackson shows an endoscopic bite block that includes a strap for holding the bite block in position. It also includes what are apparently material-saving openings formed in the flange on opposite ends of the mouthpiece, but those openings are of inadequate size to accommodate fingers. The mouthpiece of the Jackson device is elliptical in shape, apparently because that is the general shape of a slightly opened mouth, and because an ellipse provides a reasonably flat surface to support both the patient's upper and lower teeth.
Another U.S. design patent of interest is U.S. Pat. No. 297,665. U.S. utility patents of interest include U.S. Pat. Nos. 4,249,529, 4,744,358, 4,425,911, 4,867,154, 3,422,817, 4,502,478, 4,986,815, 4,191,180, and 4,732,147.
The known bite blocks cannot accommodate certain medical instruments because their openings are too small. For example, no bite block heretofore known can accommodate a #60F bougie dilator.
Another shortcoming of known bite blocks arises from the way they are held onto a patient's head. Typically, the bite block is held into position by an elongate strap; a first end of the strap engages a first end of the bite block, the medial part of the strap extends around the back of the patient's head, and a second end of the strap engages a second end of the bite block. Thus, one end of the strap will almost always lie under a patient's head when the patient's head is resting on a pillow; thus, the health care provider must move the patient's head to attach the strap to the bite block.
The ideal bite block would allow the physician's fingers to guide the instrument without restriction, and would not fall into the patient's mouth even when the patient's lips were pulled back to their limit. It would also have an instrument insertion opening of round configuration to better accommodate instruments of the type inserted through the access opening of a bite block, but would provide upper and lower flat surfaces for supporting the patient's upper and lower teeth, respectively. Moreover, it would also allow insertion of a dilator up to #60F. The ideal bite block would also be very comfortable for the patient, and would be designed so that the health care provider would not need to move the patient's head to secure the strap. However, the prior art, considered as a whole as required by law, neither taught nor suggested to those of ordinary skill in the art of bite block design, at the time the present invention was made, how the ideal bite block could be created.